1. Field of the Invention
The invention relates generally to the field of optically readable message cards and templates therefor, and, more particularly, to a novel arrangement of marking areas on the message card and the corresponding novel arrangement of openings in the template, and also to a novel template assembly for holding the message card and to a method of making the assembly.
2. Description of the Prior Art
In the prior art, the marking openings in the columns of a card marking template have been mostly horizontally-extending openings, for example, as shown in U.S. Pat. No. 2,525,837 issued Oct. 17, 1950. The resulting horizontal or slanted marks on the card which were used for electrically conductive mark-sensing, are not optically readable by commercially available more recent optical mark readers, such as IBM type 2501, 2502 or 3505. These readers require vertical marks. Using vertical openings for adjacent marking positions in a template of prior art is not feasible since the mark itself must be 0.170 inch long and the openings must extend at least 0.040 inch on each side of the mark to assure that good marks are made even with a dull pencil.
Since the distance between the centers of two vertically adjacent vertical marks is 0.250 inch, adjacent vertical openings would form one continuous slot instead of individual openings for each mark.
Although horizontal, as well as slanted, marks can be optically read by a more expensive, older IBM type 1287 optical scanner, they would require a template with widely spread out columns of openings in order to provide sufficient strength of said template and minimize errors.